Electric switch



"ETIITII/ LIER ELECTRIC SWITCH. APPLICATION FILED MAY I2| I9I7.

Patented Aug. 29, 1922.

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'untreu sTAiEs PATENT OFFICE.

ROBERT E. MILLER, 0F DETROIT, MICHIGAN, A SSIGNOR T0 EETROIT STOVE WORKS2 OF DETROIT, MICHIGAN, A CORYORATION OF MICHIGAN.

" ELECTRIC SWITGH.

Application le'd May 12,

mechanical movement therefor.

Among the objects of the invention are to provide an improved andsimplified switch and operating mechanism of the snap-switch type; to soconstruct and arrange theparts that the switch can be operated-byturning the knob or handle in either direction, and preferably, to aplurality of different pos1- tions of adjustment when operated ineitherdirection; to provide an'improved construction in which a handle of thetype such as used on gas stoves can be employed; to pro- Y plate in avdifferent position of adjustment;

Figure 4 is a perspective view looking` vide an improved and simplifiedmechanical movement for automatically locking the switch in its variouspositions of adjustment; and in general to provide animproved andsimplified switch and operating mechanism therefor of the characterabovereferred to. l

In the drawings: I j

Figure l is a vertical ysectional view through an electric switchembodying my invention;

Figure 2 is a sectional plan view.

Figure 3 is a plan view showing thecam upward on a part of themechanism;

Figure 5 is a perspective .view of thestop plate;

.Figure 6 is a view similarto Figure 3 showing the cam plate in stillanother position of adjustment.

Describing in detall the construction vshown in the'drawings, Adesignates the base of the switch, .which base isl preferably formed ofhard rubber or other-suitable insulating material. vThis base isrecessed at B to receive a part of the` locking mechanism,\leavng a'circularange C to which there is secured at various points the contactmembers D. The latter are provided with one or more arms D and D2 withwhich Specification of Letters Patent. Patented Aug- 29, 1922 1917.Serial No. 168,155.

there cooperate the movable contacts E and E There are, 1n theparticular construetion shown, two sets of these movable contacts E andE which are formed on plates the metal plate L. This plate is fixed tothe bushing member H, which is loosely sleeved upon the operating shaftM.' The latter at its upper or outer end is provided with an operatinghandle M, while near its other end it is provided with a flat surfacelVI2 over which there is slidably mounted a plate N spaced from theplate L by means of a spacing Washer or bushing N. Surrounding thebushing N is a coil spring O having its opposite ends O" and O2extending upon opposite sides of a downwardly-projecting lug Ls on theplate L." An upwardly-extending lug N2 preferably formed integral withthe plate N also extends between the ends 0 and 02. The under side ofthe plate N has a pin N"8 extending into a slot Q in the stop plate Q,whereby the rotation ofsaid plate and hence l of the stem M is limitedby contact of sai pin with the ends of said slot.

v 'As shown in Figure 5, this stop plate, in addition to the curved slotQ', hasa plurality of stops Q2, Q3, Q4 and Q5 positioned at various`points near its periphery. These stops form the part of the lockingmechanism by which the switch is held in its vari- `ouslpositions ofadjustment and cooperate with lugs R and R on the cam plates Rg and R3respectively.

As shown in Figure 6 these lugs on the cam plates have shoulder portionsR4 and R5 whichengage opposite sides of the stationary stops wheneverthe ends of the spring- O are not under tension. These plates are eachprovided with elongated slots S through which the shaft M extends and attheir rear ends with grooves vor recesses S and S2 intol which the ,lugL3 projects. Near their opposite ends 'the cam plates R2 and R3 areprovided with-slots V and V which have %ppositely positionedenlargements V2' and The operation of the switch and locking mechanismabove described is as follows: Assuming that the handle is rotated in aclockwise direction from the position shown` in-Figure 2, it will carrywith it the plate N and as the projection N2 extends between the ends ofthe spring O, it will spread apart these ends and thus tension thespring upon the initial movement. The continued movement of the handle,vshaft and plate will -then, through the actionof the pin N3 in thevslot V, first withdraw the plate R2 and then the plate R3. As soon asthe plate Ra is drawn to a position where its shoulder R5 is out ofengagement with the stop Q3,

after the handle is rotated. As the rriovable contacts E and E aresecured -to rotate with the plate` L the switch will be thus snappedfrom one position to another, and it is obvious that owing to thereversed relation of the slots in the cani plates'it is immaterialinwhich direction the switch is rotated. Also the construction is onewhich can be used on electric ranges or ovens and permits the employmentof a handle such as is ordinarily used in turning on a gas burner.

able about the axis of said stem, corresponding stationary contactscarried by said base and successively engageablevby the rotativecontacts, a plate stationary upon the ase having stops thereoncorresponding to the stationary contacts, mechanism selectivelyengageable with saidstops for holding the rotative contacts in theirvarious positions, said mechanism being releasable by said stein, aspring for actuating a snap movement of a rotative contact 'in eitherdirection stressed b initial rotation of the stem prior to releasing ofthe locking mechanism, and a pin rotatively actuable by the stemengaging in a slot of the vstop-carr fin plate to limit rotation of thestem 1n eit er direction.

2; In. an electric switch, the combination with a base, of la sternrotatively carried by said base, a plurality of contacts rotatable aboutthe axis of the stem. corresponding contacts stationary upon thevbaseand engageable by the rotative contacts, a spring for actuating a-snapmovement of the rotative contacts in either direction stressed byinitial rotation of the stem, a locking mechanism comprising a series ofstops corresponding to the several circuit closing po;

sitions of the rotative contacts, and a pairl of camplates respectivelyhaving shoulders for engagement at opposite sides of one of.'

said stops, and connected to said rotative contacts, a means actuable byrotation of said switch, subsequent to stressing of said spring, tosuccessively withdraw said` cam plates from the engaged stop, andthereby permit actuation of the rotative contacts by the spring. n 3. inan electric switch, the combination with a base, of a stem rotativelycarried by said base, `-a plurality of contacts rotatable about the axisof the stem, corresponding contacts stationary upon the base andengageable by the rotative contacts, a spring for actuating a snapmovement of the rotative contacts in either direction stressed byinitial rotation of the stem, a locking mechanism comprising a series ofstops corre-l sponding to the several circuit closing positions of therotative contacts, and a pair of cam plates respectively havingshoulders for engagement at opposite. sides of one of said stops, andconnected to said rotative contacts, said plates respectively having camslots, and a pin rotative with the stem engaging in the slots of both ofsaid plates, for withdrawing said plates from the engaged stopsubsequent to stressing of said spring and thereby permitting actuationof the rotative contacts by the spring.

In testimony whereof I affix my signa-- ture in presence of twowitnesses.

ROBERT H. ,MILLER Witnesses:

ARTHUR D. PULVER, FRANK G. WELBON.

